8.5 Naming a ‘Top’ Node

Ordinarily, you must always name a node in a cross reference.
However, it’s not unusual to want to refer to another manual as a
whole, rather than a particular section within it. In this case,
giving any section name is an unnecessary distraction.

So, with cross references to other manuals (see Four and Five Arguments), if the first argument is either ‘Top’ (capitalized
just that way) or omitted entirely, and the third argument is omitted,
the printed output includes no node or section name. (The Info output
includes ‘Top’ if it was given.) For example,

@xref{Top,,, make, The GNU Make Manual}.

produces

*Note (make)Top::.

and

See The GNU Make Manual.

Info readers will go to the Top node of the manual whether
or not the ‘Top’ node is explicitly specified.

It’s also possible (and is historical practice) to refer to a whole
manual by specifying the ‘Top’ node and an appropriate entry for the
third argument to the @xref command. Using this idiom, to
make a cross reference to The GNU Make Manual, you would write:

@xref{Top,, Overview, make, The GNU Make Manual}.

which produces

*Note Overview: (make)Top.

in Info and

See section “Overview” in The GNU Make Manual.

in a printed manual.

In this example, ‘Top’ is the name of the first node, and
‘Overview’ is the name of the first section of the manual. There
is no widely-used convention for naming the first section in a printed
manual, this is just what the Make manual happens to use. This
arbitrariness of the first name is a principal reason why omitting the
third argument in whole-manual cross references is preferable.